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stresses in the Scapular Fossa Do Not Exceed the yield stress When Elevated up to 135 Degrees of Abduction after Reverse Shoulder Arthroplasty

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Journal of Biomedical Science and Engineering 2024年第2期17卷 35-40页

作者： Rina Sakai Tomonori Kenmoku Ryo Tazawa Kazuhiro Yoshida Tomomi Mizuhashi Masanobu Ujihira Department of Medical Engineering and Technology Kitasato University School of Allied Health Sciences Sagamihara Japan Department of Orthopedic Surgery Kitasato University School of Medicine Sagamihara Japan Kitasato University Graduate School of Medical Sciences Sagamihara Japan

Reverse shoulder arthroplasty (RSA) is an effective treatment for rotator cuff tears. Despite its advantages, complications occur at a high rate. Complications requiring revision include a high rate of base plate failure, 38% of which are due to instability. The primary stability the base plate ensures is a crucial factor and, thus, is the subject of much debate in clinical studies and biomechanical research. This study is aimed to provide data that will contribute to the base plate’s pri-mary stability and glenoid longevity by clarifying the stresses at the scapular fossa and base plate interface associated with elevation after RSA. A 3D finite element model was created from the DICOM data for the scapulohumeral joint and SMR shoulder system. For loading conditions, 30 N was applied for each posi-tion with abduction angles of 0, 45, 90, and 135 degrees. A three-dimensional fi-nite element analysis was performed using the static implicit method with LS-DYNA. The von Mises stresses in the scapular fossa were found not to exceed the yield stress on the bone even after elevation to an abduction angle of 135 de-grees after RSA. It is rough to uniformly compare the yield stress and the von Mises stress, but it was inferred that the possibility of fracture is low unless a large external force is applied. A maximum von Mises stress showed 0 degrees of abduction, suggesting that the lowered position is in a more severe condition than the elevated position. If better improvement is desired, it may be necessary to devise ways to reduce the stress on the upper screw. .

关键词： Reverse Shoulder Arthroplasty Finite Element Analysis yield stress Glenoid

Correlation Between yield stress of Silty Mud Sediments and Continuous Oscillatory Shearing Properties

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China Ocean Engineering 2022年第2期36卷 223-232页

作者： CHEN Xiao-hui ZHANG Min-xi YUE Shao-lin ZHOU Huan YU Guo-liang SKLOE CISSEDepartment of Ocean and Civil Engineering Shanghai Jiao Tong UniversityShanghai 200240China CCCC Road&Bridge Special Engineering Co. Ltd.Wuhan 430061China

Analyzing the rheological properties of silty beds subjected to continuous oscillatory shear loading is crucial for understanding the morphological deformation of the seabed and ensuring safety in geological and marine engineering applications.In this study,the effects of oscillatory shearing properties on the yield stress(S_(u))of silty sediments were quantitatively investigated.The effects of oscillatory shear strength(0-3),water content(26.6%-70.84%),and particle diameter(8.79-50μm)were examined extensively through a series of laboratory tests.The results indicated that the three aforementioned parameters were the major factors that affected the rheological characteristics of silty sediments.Furthermore,their effects could be elucidated using the yield stress of cohesive sediments as the indicator parameter.The ratio of yield stress(S_(u)/S_(u0))varied as the oscillatory shear strength increased up to a critical value,Λ_(cr).S_(u)bsequently,the ratio remained at a constant value.It was deduced that the yield stress decreased with increasing oscillatory shear strength forΛΛ_(cr),the sediments entered an equilibrium fluidization stage,and the yield stress remained almost constant,irrespective of the oscillatory shear strength.Furthermore,during the equilibrium fluidization stage,it was observed that the ratio S_(u)/S_(u0)did not vary with water content but decreased as the particle diameter increased.Finally,based on regression analysis of the experimental data for non-equilibrium and equilibrium fluidization stages,a correlation between yield stress of silty sediments and continuous oscillatory shearing properties was proposed.This correlation can aid in understanding the changes in solid resistance and assessing safety in piling engineering.Furthermore,it can provide a theoretical guidance for reducing soil resistance in marine structures using mechanical vibrations.

关键词： silty sediments yield stress water content particle diameter oscillatory shear strength

Effect of particle gradation characteristics on yield stress of cemented paste backfill

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International Journal of Minerals,Metallurgy and Materials 2020年第1期27卷 10-17页

作者： Hai-yong Cheng Shun-chuan Wu Xiao-qiang Zhang Ai-xiang Wu Faculty of Land Resources Engineering Kunming University of Science and TechnologyKunming 650093China Key Laboratory of Ministry of Education of China for Efficient Mining and Safety of Metal Mines Beijing 100083China

Along with slurry concentration and particle density,particle size distribution(PSD)of tailings also exerts a significant influence on the yield stress of cemented paste,a non-Newtonian fluid.In this work,a paste stability coefficient(PSC)was proposed to characterize paste gradation and better reveal its connection to yield stress.This coefficient was proved beneficial to the construction of a unified rheological model,applicable to different materials in different mines,so as to promote the application of rheology in the pipeline transportation of paste.From the results,yield stress showed an exponential growth with increasing PSC,which reflected the proportion of solid particle concentration to the packing density of granular media in a unit volume of slurry,and could represent the properties of both slurry and granular media.It was found that slurry of low PSC contained extensive pores,generally around 20μm,encouraging free flow of water,constituting a relatively low yield stress.In contrast,slurry of high PSC had a compact and quite stable honeycomb structure,with pore sizes generallyyield stress to flow.

关键词： paste backfill grading theory yield stress paste stability coefficient microscale

Statistical Characterization of the yield stress of Nanoparticles

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Acta Mechanica Solida Sinica 2021年第2期34卷 149-156页

作者： Liang Yang Jianjun Bian Weike Yuan Gangfeng Wang School of Materials Engineering Jiangsu University of TechnologyChangzhou 213001China Department of Engineering Mechanics SVLXi'an Jiaotong UniversityXi'an 710049China

Atomistic simulations are performed to study the statistical mechanical properties of gold nanoparticles.It is demonstrated that the yielding behavior of gold nanoparticles is governed by the dislocation nucleation around surface steps.Since the nucleation of dislocation is an activated process with the aid of thermal fluctuation,the yield stress at a specific temperature should vary statistically rather than being a definite constant value.Molecular dynamics simulations reveal that the yield stress follows a Gaussian distribution at a specific temperature.As the temperature increases,the mean value of yield stress decreases while the width of distribution becomes larger.Based on the numerical analysis,the dependence of mean yield stress on temperature can be well described by a parabolic function.This study illuminates the statistical features of the yielding behavior of nanostructured elements.

关键词： yield stress Gold nanoparticle Molecular dynamics Gaussian distribution

Changes in underflow solid fraction and yield stress in paste thickeners by circulation

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International Journal of Minerals,Metallurgy and Materials 2021年第3期28卷 349-357页

作者： Hong Li Ai-xiang Wu Hong-Jiang Wang Hui Chen Liu-Hua Yang Key Laboratory of Ministry of Education for Efficient Mining and Safety of Metal Mines University of Science and Technology BeijingBeijing 100083China School of Civil and Resource Engineering University of Science and Technology BeijingBeijing 100083China Shandong Taikai Power Electronic Co. Ltd.Taian 271000China

The trouble-free and efficient operation of paste thickeners requires an optimal design and the cooperation of each component.When underflow discharging is suspended,alleviating the vast torque that the remaining solids within the thickeners may place on rakes mainly lies in the circulation unit.The mechanism of this unit was analyzed,and a mathematical model was developed to describe the changes in underflow solid content and yield stress.The key parameters of the circulation unit,namely,the height and flow rate,were varied to test its performance in the experiments with a self-designed laboratorial thickening system.Results show that the circulation unit is valid in reducing underflow solid fraction and yield stress to a reasonable extent,and the model could be used to describe its efficiency at different heights and flow rates.A suitable design and application of the circulation unit contributes to a cost-effective operation of paste thickeners.

关键词： paste thickener circulation unit solids content yield stress rake failure

Characterization of yield stress Development of Cement Paste by Electrical Resistivity

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Journal of Wuhan University of Technology(Materials Science) 2017年第6期32卷 1361-1367页

作者： Mbujje Joel Webster 魏小胜 ZHOU Kongjin School of Civil Engineering and Mechanics Huazhong University of Science and Technology Wuhan 430074 China State Key Laboratory of Silicate Wuhan University of Technology Wuhan 430070 China

yield stress development of cement paste is potentially governed by percolation of 3-dimensional links formed by hydration products on the surface of the particles. It rises steadily at a gradual rate before a sudden increase in rate of growth. In this study, a method was proposed to predict the yield stress development based on the diameter of spread（D） of mini slump cone test and gradient from electrical resistivity measurement（Km）. To evaluate the significance of（D） and（Km） in terms of yield stress, they were quantitatively compared to the initial yield stress（τ0） and rate of yield stress growth（K） obtained from a rheometer. A mathematical relationship between the yield stress of cement paste, diameter of spread and electrical resistivity characteristic gradient was developed. The equation developed can be used as an alternative method to estimate yield stress of cement paste.

关键词： fly ash electrical resistivity rheology yield stress

Inherent relations between yield stress and stability of bubble petroleum coke water slurry

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Petroleum Science 2018年第1期15卷 157-163页

作者： Fu-Yan Gao Eric J.Hu Ningbo Institute of Technology Zhejiang University School of Mechanical Engineering The University of Adelaide

The stability of petroleum coke water slurry（PCWS） is currently a hot topic. The inherent relationship between yield stress and stability of bubble-PCWS was studied through orthogonal experiments and range analysis in this work. The results showed that the stability of bubble-PCWS was positively related to the yield stress and that the yield stress could be greatly impacted by the operation conditions during preparation of bubble-PCWS. The main factors affecting the yield stress of bubble-PCWS were solid concentration, aeration time and dosage of frother. However, the effects of aperture size of air distribution plates and type of frother on the yield stress were slight within the experimental range. The optimal conditions for the greatest yield stress were as follows： aeration time of 30 min, solid concentration of 65 wt%, frother dosage of0.030 wt% of the air-dried pulverized petroleum coke, aperture size of air distribution plate of 2-5 lm and AOS frother.The yield stress and the pour rate of bubble-PCWS under this optimum operation condition could reach maxima of more than 0.4 Pa and 96%, respectively.

关键词： Petroleum coke Petroleum coke water slurry （PCWS） Stability yield stress Orthogonal experiment

Influence of chemical reaction on heat and mass transfer of non-Newtonian fluid with yield stress by free convection from vertical surface in porous medium considering Soret effect

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Applied Mathematics and Mechanics(English Edition) 2010年第6期31卷 675-684页

作者： F. S. IBRAHIM F. M. HADY S. M. ABDEL-GAIED M. R. EID Department of Mathematics Faculty of Science Assiut University Department of Science and Mathematics Faculty of Education Assiut University

The effect of chemical reaction on free convection heat and mass transfer for a non-Newtonian power law fluid over a vertical flat plate embedded in a fluid-saturated porous medium has been studied in the presence of the yield stress and the Soret effect. The governing boundary layer equations and boundary conditions are cast into a dimen- sionless form by similarity transformations, and the resulting system of equations is solved by a finite difference method. The results are preSented and discussed for concentration profiles, as well as the Nusselt number and the Sherwood number for various values of the parameters, which govern the problem. The results obtained show that the flow field is influenced appreciably by the presence of the chemical reaction parameter γ the order of.the chemical reaction parameter m, the Soret number St, the buoyancy ratio N, the Lewis number Le, and the dimensionless rheological parameter Ω.

关键词： non-Newtonian fluid free convection chemical reaction yield stress Soret effect

Synergistic effect of magnetic field and nanocomposite pour point depressant on the yield stress of waxy model oil

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Petroleum Science 2020年第3期17卷 838-848页

作者： Hui-Rong Huang Wei Wang Ze-Heng Peng Kai Li Yan-Fen Ding Wei-Jie Yu Dong-Ying Gan Chuan-Shuo Wang Yi-Han Xue Jing Gong Beijing Key Laboratory of Urban Oil and Gas Distribution Technology MOE Key Laboratory of Petroleum EngineeringNational Engineering Laboratory for Pipeline SafetyChina University of PetroleumBeijing 102249People's Republic of China Beijing National Laboratory for Molecular Sciences Key Laboratory of Engineering PlasticsInstitute of ChemistryChinese Academy of SciencesBeijing 100190People's Republic of China

yield stress,as the key parameter to characterize the network strength of waxy oil,is important to the petroleum pipeline safety.Reducing the yield stress of waxy oil is of great significance for flow assurance.In this study,the effect of alternating magnetic field(intensity,frequency)on the yield stress of a waxy model oil with nanocomposite pour point depressant(NPPD)is systematically investigated.An optimum magnetic field intensity and frequency is found for the reduction in yield stress.When adding with NPPD,the heterogeneous nucleation of NPPD contributes to the reduction in yield stress for waxy model oil.Interestingly,the magnetic field is helpful for the modification of yield stress at a lower frequency and intensity before the optimal value;however,the modification is found to be weakened when the magnetic field is further increased after the optimal value.Possible explanation is proposed that the aggregation morphology of wax crystal would be altered and results in the release of wrapped oil phase from the network structure under the magnetic field.

关键词： Magnetic field Nano composite yield stress Waxy model oil